| Combinatorial control of the bradykinin B 2 receptor promoter by p 53 , CREB , KLF 4 , and CBP : implications for terminal nephron differentiation . ^^^ Several lines of evidence indicate that cooperative interactions among the three transcription factors occur in vivo during terminal nephron differentiation : 1 ) CREB , p 53 , and KLF 4 are coexpressed in B2R positive differentiating cells ; 2 ) the maturational expression of B2R correlates with CREB / p53 / KLF 4 DNA binding activity ; 3 ) assembly of CREB , p 53 , and KLF 4 on chromatin at the endogenous B2R promoter is developmentally regulated and is accompanied by CBP recruitment and histone hyperacetylation ; and 4 ) CREB and p 53 occupancy of the B2R enhancer is cooperative . ^^^ These results demonstrate that combinatorial interactions among the transcription factors , CREB , p 53 , and KLF 4 , and the coactivator CBP , may be critical for the regulation of B2R gene expression during terminal nephron differentiation . . ^^^ |